Dual Closed-Loop Linear Active Disturbance Rejection Control of Grid-Side Converter of Permanent Magnet Direct-Drive Wind Turbine

Abstract

In the permanent magnet direct-drive wind power grid-connected system, in order to solve the coupling problem between d -axis and q -axis currents and to improve the disturbance rejection performance of direct current (DC) bus voltage under grid faults, a new dual closed-loop structure based on linear active disturbance rejection control (LADRC) is proposed. This new dual closed-loop control includes current inner loop decoupling control and DC bus voltage outer loop control with first-order LADRC. As the LADRC has the advantages of decoupling and disturbances rejection, it is applied to the control of wind power grid-connected inverter. Through analysis, it is demonstrated that the current decoupling control is simpler than proportional integral (PI) control algorithm, the dynamic response speed is faster, and the DC bus voltage control has better anti-disturbance. Finally, a 1.5 MW direct-drive permanent magnet wind power system was established through digital simulation, and the control effects of the two control modes under different working conditions are compared. The simulation results verify that the proposed dual closed-loop control based on first-order LADRC is superior to PI double closed-loop control in terms of decoupling performance and disturbance rejection performance under grid faults.

Keywords

• wind power grid-connected inverter
• double closed-loop control
• linear active disturbance rejection control
• current decoupling control
• disturbance rejection performance